Civic door panels

Does anyone know what the foam inserts in the Civic door panels are for?  I just got done deadening the driver's side door and didn't realize I needed a cutout for the big foam insert in the  door panel.  Now I have to decide if I want to cut into my nice new sound deadening or if I can just cut out the foam insert.  I don't have power windows or locks, so there's no wiring or anything in there.  I can't imagine that insert is very useful.

BTW, my car is a 2004 Civic VP 4 door sedan, but I imagine that most of the 2001-up Civics are the same.

Thanks!

The foam is usually just an insert for the spaces in the metal of the door that is designed to reduce noise and vibration in the door panel.  Just shave it off.  You want a perfect seal on your door panel, so don't cut a hole for the insert.

Sorry to ask so many questions, but I looked all over the internet and couldn't find the answer to this one:

When you deaden your doors and cover an access hole with the mat, should you leave the backing on where the mat lays accross the hole, or should you remove it?  I was thinking that it should stay on since the mat isn't actually going to be sticking to anything.  I live in Florida, so when some rolls around, it could get ugly if there are sections of adhesive that aren't stuck to anything.

Thanks again!

It wouldn't hurt either way, because there is nothing back there to get attached to it except some random debris floating around inside the door panel.  You could stick some of the factory weather stripping to the adhesive side if that is a concern.  When I deaden doors, I take off the factory plastic weatherguard and apply a few layers of sound deadening  to both the exterior and interior doorskins.